1902] BINUCLEATE CELLS IN HYMENOMYCETES 19 
The subhymenial cells of C. ephemerus show very conspicuous 
disc- or saucer-shaped bodies arranged in pairs on opposite 
sides of their walls. These bodies stain deeply and are very 
numerous, lying on all sides of the hyphal cells wherever the 
walls of adjacent cells are in contact. /ig. rg shows two pairs 
of such bodies and their relative position with reference to the 
cell walls. Strasburger (15, p. 335) has described similar struc- 
tures. They doubtless mark points where the walls are perfo- 
rated in some fashion, thus establishing connection between 
adjacent cells. I have described such bodies for Pyronema (5), 
and also spherical granules which may have a similar signifi- 
cance. 
Brefeld (1) has described the carpophore of C. stercorarius 
as arising from a single hypha of the vegetative mycelium. This 
hypha produces a richly developed system of branches which 
arrange themselves ultimately into the parts of the young carpo- 
phore. Vegetative growth of the mycelium and formation of the 
carpophore are thus seen in this case to be rather sharply separ- 
ated, and it might well be that at this point the transition from 
uninucleated to binucleated cells is effected. However, no such 
differentiation of mycelial growth and carpophore formation 
exists in Hypochnus, whose mycelium is binucleated throughout 
in its mature condition. Maire says nothing as to the stage 
when the binucleated cells first appear in Coprinus. | If his state- 
ment is true, that the mycelium of the latter plant is made up of 
uninucleated cells, it differs, as noted, from Hypochnus in this 
respect. Whether Hypochnus or Coprinus would represent the) 
more primitive condition in this particular is not easily to be 
determined with certainty. Most mycologists, however, have 
agreed so far in regarding the Tomentelleae as primitive Basidio- 
mycetes, and the Agarics as among the most specialized forms ; 
and, in the absence of positive evidence to the contrary, this seems 
the most natural assumption. _ Still, it is quite possible that the 
Hypochnus type may be degenerate in certain particulars and 
may have lost a mycelium of uninucleated cells, such as Maire 
reports for Coprinus radiatus. Just where in this case the 
